In order to use interventional devices in tubular structures where the location of the device is not visible to the user from the outside of the object, the user is provided with information about the location of the device in relation to the object. For example, during neurological interventions, devices are routinely used in the treatment process of diseased vessels. In order to assist the physician, for example a neurosurgeon, with navigating a specific device to the diseased vessel segment, the device and region of interest are visualized using X-ray imaging. For example, this is achieved by two-dimensional X-ray projection images, a disadvantage of which is that the true three-dimensional nature of the vessels is lost. This may lead to distorted visualization of, for example, vessel segment length, vessel branching angles and vessel tortuosity. This may hamper navigation of the device through the vessels. An example for applying information for navigation purposes is the so-called road mapping functionality. From an available 3D vessel representation, a projection image that matches the current viewing angle of the X-ray apparatus is created. This artificial projection image is then overlaid and registered on live X-ray fluoro images to provide the physician with the road map during device navigation. For example, EP 0 809 211 A2 describes to form and store a series of 2D X-ray images of an object, to form a 3D image, to extract a relevant structure from the 3D image and to calculate a series of the synthetic 2D projection images of the extracted structure, wherein the structure is projected with the same geometrical parameters as used for the structure during the formation of the individual X-ray images. Further, the synthetic projection images and the processed X-ray images are superimposed.